Hey Guys,
I have a 2008 Jeep Grand Cherokee 5.7L and the Red warning light on the cluster is on. The light is intermittent and there seems to be no logic to when it comes on and goes off. The Light is solid while the vehicle is stopped/parked and flashes with a chime when i drive. Its came on after a huge snowfall 2 weeks ago...eventually it did go off(The same night it also flashed service abs and service 4wd but those messages disappeared a few seconds later and I had a battery voltage issue and car died after starting and stopping a couple of times, This left a check eng low voltage code which i reset and nothing since then - Not sure if this is related) about 2-3 days after the first incident the light came on and its been there since then flashing and chiming while driving

I have already gone through the usual suspects. I have disconnected the parking brake switch on the lever. Disconnected the float switch on the reservoir. Checked fluids, hubs for leaks etc.... The car runs and drives normally and the brakes feel fine.
So short of being a "short" in most likely the parking brake switch...is there any other reason why this would happen.

Thanks

Madanio24

02-21-2013 09:20 PM

Re: Red Brake Warning light on dash

most likely a bad speed sensor. also check battery voltage because GC frak out with low voltage

Lucas J

02-21-2013 09:34 PM

Re: Red Brake Warning light on dash

Quote:

Originally Posted by Madanio24
(Post 764970)

check battery voltage because GC frak out with low voltage

x2

I have had a similar problem because of the battery.

SvenskaJeepGuy

02-22-2013 01:30 AM

Re: Red Brake Warning light on dash

Likely battery or alternator. Remove the negative terminal while running to see if the jeep dies

kennzz05

02-22-2013 04:03 AM

Re: Red Brake Warning light on dash

Quote:

Originally Posted by SvenskaJeepGuy
(Post 765100)

Likely battery or alternator. Remove the negative terminal while running to see if the jeep dies

while im no expert i have read many times to NOT EVER DO THAT to a modern vehicle it can cause all kinds of issues with all the computers on the vehicle
and frankly if it were the alternator the whole dash would be lit up with all the lights not just brakes a simple meter can tell if its the alternator this isnt 1970 and unhooking the battery while running just dosent sound like a great idea perhaps that works for you but ill use a meter instead

gavin

02-22-2013 01:06 PM

Re: Red Brake Warning light on dash

Thanks for the responses! The voltage while I crank the engine hit 9.36V and thats after driving around for about 30 minutes.... which doesn't necessarily means a bad battery(its really cold outside) but i'm taking it to a shop to get bench tested anyways.
I agree with not disconnecting the battery while the alternator is running...the battery acts as a shock absorber for your entire electrical system..you can very easily damage the many modules in it.
Thanks again for the direction. Will post my findings.

Madanio24

02-23-2013 12:04 AM

Re: Red Brake Warning light on dash

This is what you do to test your alternator. While the jeep is running take the rubber car off the alternator and measure the voltage on that. it should be above 12 volts usually in the 13-14 range. If its in that range your alternator is fine.

gavin

02-23-2013 10:25 AM

Re: Red Brake Warning light on dash

ok so I bought a new battery and the issue still prevails. I got a buddy at chrysler to scan the vehicle and there were no codes for it. Ok another thing i noticed is that when the warning light comes on the daytime running lights switch off..(in my experience this usually happens when the park brake is used) maybe i do have a short?! Also would an intermittent brake fluid sensor cause the chime to go off and the DRLs to switch off? Thanks.